1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Book project: where the land is greener - Case Studies and Analysis of Soil and Water Conservation Initiatives Worldwide (where the land is greener)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

GEOTEST AG (GEOTEST AG) - Switzerland

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

01/09/2003

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

Integrated gully treatment consisting of several simple practices including stone and wooden check dams, cut-off drains and reforestation in sediment traps (biotrampas).

2.2 Detailed description of the Technology

Description:

The focus of the case study is a degraded catchment, located at high altitude (2,800–4,200 m a.s.l.), home to 37 households, which is characterised by severe gullies and landslides. Gullies are continuously expanding, and constitute a significant proportion of the catchment. These cause considerable loss of cropland as well as downstream damage to the city of Cochabamba.
A combination of structural and vegetative measures was designed and implemented with the purpose of: (1) preventing affected areas from further degradation by safely discharging runoff from the surrounding area through the main gullies down to the valley; (2) gradually stabilising the land through the regeneration of vegetative cover; (3) reducing downstream damage through floods and siltation; (4) ensuring accessibility to the mountainous agricultural area during the rainy season.
Cut-off drains at the heads of the gullies, reinforced with stones inside the channel and grassed bunds below, concentrate runoff and cascade it down over stone steps back into the waterways. Flow is controlled by stone and wooden check dams and discharged safely. Sediment is trapped behind these structures and terraces develop. Bushes or trees are planted above and below the check dams. Depending on availability of materials, wooden check dams are sometimes used and associated with tree planting (four trees above and four below each check dam).
These practices are complemented by SWC measures throughout the catchment: biotrampas are staggered sediment traps located on the steep lateral slopes. They comprise ditches behind wooden barriers where soil accumulates. Biotrampas create suitable sites for tree/bush planting while stabilising the hillsides, reducing erosion, increasing infiltration and slowing siltation of the check dams in the watercourses. Supporting technologies include fenced-off areas for reforestation of the lateral slopes/upper edge of the gully, and finally large gabion dams at the outlets of the gullies, usually 10-25 m in length, but exceptionally up to 200 m.
After a few years vegetation should have stabilised the system, and effectively replaced the wooden and stone constructions. The various practices enhance each other. Establishment is labour demanding, but other costs are low, as long as the material in question is locally obtainable. Maintenance costs are also low. The technology was implemented over a period of six years, starting in 1996, through the Programa de Manejo Integral de Cuencas (PROMIC).

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation

3.2 Current land use type(s) where the Technology is applied

Comments:

Major land use problems (compiler’s opinion): Deforestation, overgrazing and poorly managed channel irrigation in areas with steep slopes: poorly structured soils and
extreme climatic variability causing erosion gullies, landslides, downstream flooding and sedimentation of agricultural land and settlements - including the city of Cochabamba.

Other grazingland: extensive grazing

3.3 Further information about land use

Water supply for the land on which the Technology is applied:

• rainfed

Specify:

Longest growing period in days: 210 Longest growing period from month to month: Oct - Apr

3.4 SLM group to which the Technology belongs

• cross-slope measure
• water diversion and drainage

• Sediment traps

3.5 Spread of the Technology

Comments:

Total area covered by the SLM Technology is 6 m2.

3.6 SLM measures comprising the Technology

3.7 Main types of land degradation addressed by the Technology

Comments:

Main type of degradation addressed: Wg: gully erosion / gullying, Wm: mass movements / landslides, Wo: offsite degradation effects, Bq: quantity / biomass decline

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• restore/ rehabilitate severely degraded land

4.1 Technical drawing of the Technology

4.2 Technical specifications/ explanations of technical drawing

Gully control and catchment protection: an overview of the integrated measures.

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: reduction of slope angle, reduction of slope length, improvement of ground cover, increase in organic matter, sediment retention / trapping, sediment harvesting, control of concentrated runoff

Secondary technical functions: increase of infiltration, control of dispersed runoff

Vegetative measure: grassed bunds
Vegetative material: G : grass

Vegetative measure: aligned trees
Vegetative material: G : grass

Vegetative measure: Vegetative material: G : grass

Vegetative measure: Vegetative material: G : grass

Structural measure: cut-off drains

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	Plant local bushes and trees in front and behind the biotrampas andthe check dams (after sedimentation). Altitude acclimatisation (2 weeks)is required for the trees before planting.	Vegetative
2.	Cut-off drains: excavate channel above the gully. Lay stones in the bedand plant local bushes or grass on the bund below the ditch. The outletof the ditch into the gully is stabilised by a few stone steps.	Structural
3.	Stone check dams: excavate a ditch perpendicular to the water channel	Structural	during the dry season
4.	Wooden check dams (up to 8 m long, 15–20 cm wide and 1 m high):soil excavation (see 2.). Fix logs with wire or nails to vertical poles.Position a bio-fibre fleece behind the dam to prevent sediment fromflowing through.	Structural
5.	Biotrampas: excavate soil, hammer wooden posts into the soil andfix 2–3 horizontal logs with nails or wire to the wooden posts.	Structural	(During dry season)
6.	Plant local bushes and trees in front and behind the biotrampas andthe check dams (after sedimentation). Altitude acclimatisation (2 weeks)is required for the trees before planting. Establish fences to protect the plants.	Structural

4.5 Costs and inputs needed for establishment

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Labour	ha	1.0	48.0	48.0
Equipment	Tools	ha	1.0	4.0	4.0
Plant material	Seedlings	ha	1.0	19.0	19.0
Construction material	Stone	ha	1.0
Construction material	Wood	ha	1.0	33.0	33.0
Construction material	Nails, wire	ha	1.0	2.0	2.0
Construction material	Bio-fibre fleece	ha	1.0	4.0	4.0
Total costs for establishment of the Technology					110.0

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Biotrampas: pruning the trees	Vegetative	/every three years.
2.	Cut-off drains: clearing of sediment, cutting bushes and grasses.	Vegetative
3.	Stone check dams: pruning trees and bushes. After full sedimentation, the dam may be increased in height.	Vegetative	/every three years.
4.	Wooden check dams: pruning trees and bushes	Vegetative	/every three years

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

	Specify input	Unit	Quantity	Costs per Unit	Total costs per input	% of costs borne by land users
Labour	Labour	ha	1.0	12.0	12.0	100.0
Equipment	Tools	ha	1.0	1.0	1.0	100.0
Plant material	Seedlings	ha	1.0	1.0	1.0	100.0
Construction material	Stone	ha	1.0
Construction material	Wood	ha	1.0	1.0	1.0	100.0
Construction material	Nails, wire	ha	1.0	1.0	1.0	100.0
Total costs for maintenance of the Technology					16.0

Comments:

Costs have been calculated for the whole catchment (6 km2) – including 100 m of cut-off drains, 6,750 m of stone
check dams, 1,500 m of wooden check dams and 770 biotrampas – and then divided by the number of hectares. Wood is not locally available (because of national park laws) and needs to be brought into the area. Establishment and maintenance costs were paid by PROMIC during their intervention period of 6 years. The (high) costs of the gabion weirs further downstream are not included as these are not always required and vary considerably in size from site to site.

5.1 Climate

5.2 Topography

Comments and further specifications on topography:

Slopes on average: Also very steep and hilly (both ranked 2) and moderate and rolling (both ranked 3)

5.3 Soils

If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil depth on average: Also Very shallow (ranked 2) and shallow as well as deep (both ranked 3)
Soil fertility: Low and very low
Topsoil organic matter: High (on the cropland at high altitudes) and low (in the gullies)
Soil drainage/infiltration: Medium

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Market orientation: Subsistence (mostly subsistence (self-supply) with low market income)

5.7 Average area of land owned or leased by land users applying the Technology

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• individual, titled

• communal grassland

Land use rights:

• communal (organized)
• individual

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Socio-cultural impacts

Ecological impacts

Soil

6.2 Off-site impacts the Technology has shown

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?

• 0-10%

Comments:

100% of land user families have adopted the Technology with external material support

There is no trend towards spontaneous adoption of the Technology

Comments on adoption trend: Only a few farmers have built new structures post-project. This is due to different reasons: (1) PROMIC stopped its financial support; (2) the gullied areas are not used by farmers, therefore they have little reason to protect them; (3) the catchment is w

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Reduction of landslips and flooding in the valley How can they be sustained / enhanced? New small gullies may originate inside an existing gully or around it. It is important to continue to maintain the current measures and construct new, even though the subsidies of PROMIC have been terminated.
The technology could be implemented by the farmers themselves as materials (except for wood) and tools are locally available How can they be sustained / enhanced? Prolong the sensitisation work to convince the farmers of the necessity and benefits of the technology.
Reduction of soil loss in the watershed How can they be sustained / enhanced? Do not apply the mentioned practices in isolation but always in combination.
Simple technology with high positive long-term impact, especially downstream.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
The technology doesn’t address the root cause of human induced gully erosion	Alongside the gully control technology it is necessary to apply complementary conservation measures on the cropland above the gully to prevent new gully development.
High labour input for establishment of SWC measures.	An agreement on sustainable use of trees should be made with the national park authority.
The technology partly depends on inputs that are not available locally: timber for establishment of wooden structures (which is a significant quantity) are brought in from outside (since the area is within a national park tree felling is not allowed)

7.2 References to available publications

Title, author, year, ISBN:

Documentation of PROMIC (see address above)

Available from where? Costs?

PROMIC, Programa de Manejo Integral
de Cuencas, Av. Atahuallpa final, Parque Tunari, casilla 4909, Cochabamba, Bolivia; promic@promic-bolivia.org; www.promic-bolivia.org